In this chapter, we discussed the principles of communication between microservices and various methods of communication such as synchronous or asynchronous, and communication patterns such as choreography and orchestration. We have seen the example of event-based messaging and discussed various use cases and ways of doing it. REST can be used in both types of communication: synchronous and asynchronous. There are some tools to handle both type of communication. It entirely depends on the situation and the needs of the specific project to choose one pattern over the other. In the next chapter, we will discuss how to secure the microservices with an example of our credit-scoring microservice.